An ounce of prevention

This Sunday, September 14, horse people from all over the province and beyond will descend upon the Flamboro Backstretch for the annual Canadian Yearling Sale. One thing that won’t likely be on the top of their minds: Biosecurity!

The term biosecurity usually conjures up images of people in white suits and face masks but biosecurity really refers to simple practices that prevent disease-causing germs from gaining access to a barn or farm property. The aim is not only to prevent disease in the yearlings but to prevent the spread of disease back in the barn where the hard-working racehorses are located. Yearling sales are exciting and fun but yearling sales also create the perfect storm for the spread of germs. This is why a bit of planning goes a long way. To help with the process, here are a few things to consider:

Yearlings are like young children starting school. Because the sale is usually their first trip away from home they are excited and this stress can affect the way their immune systems function. They are then placed in close contact with other excitable youngsters with naive immune systems and exposed to people arriving from various stables. In schools, the kids are taught to cough into their sleeve and use hand sanitizers frequently, not to share hats and clothing nor snacks and lunches. Yearlings, however, must rely on us to help limit the spread of germs.

Where are you going to put the newly purchased yearling(s) (and those that have been bought back)?

When the new (or returning) youngsters arrive home they are often put in the nearest empty stall but if that stall is next to your racehorse who will be “in-to-go” that week you may regret that decision. If they can’t be housed in a separate barn altogether try to group the yearlings together at one end of the barn. Ideally there should be an empty stall in between them and the racehorses. If you have no choice but to put them in amongst the racehorses extra care should be taken when handling and moving them throughout the barn. Treat the new yearlings like they are “infectious until proven otherwise” for at least two weeks. If, after this time, no illnesses have occurred the youngsters can be handled similarly to the others in the barn. If you are unsure about their health status consult with your veterinarian.

Who’s going to look after them?

Limiting the number of caretakers who look after the yearlings will help prevent spread to the racehorses. If you are the only person in the barn then you may need to change the order in which you do your barn chores so that you are dealing with the yearlings last (see below).

How are they going to be looked after?

The reason we treat new horses, like yearlings, as “infectious until proven otherwise” is that they can shed viruses and bacteria without showing any clinical signs as in the early stage of disease or if they are a carrier of a virus such as herpesvirus. To reduce the risk of exposing the other horses in the barn to any new germs it is important to feed, water and muck-out the yearlings after the other horses in the shed row have been accommodated. Either dedicated stall equipment such as wheelbarrows, forks and shovels should be used to clean the yearlings’ stalls or commonly used equipment should be cleaned after use.
Most stalls have stall gates instead of stall doors which allow the yearlings to get their noses into the space of other horses on the cross ties. Avoiding the use of ties directly in front of the yearlings for at least two weeks and dedicating those ties to the yearlings themselves can be helpful. If this is not possible and knowing that many horses put the ties in their mouth, one should disinfect the ties after each and every use. Your veterinarian should be able to guide you as to which disinfectants are safe and effective.

Handling and breaking of the yearlings to the cart should be done after the daily racehorse jogging/training sessions have been completed. Any common equipment such as bits and lead shanks should be wiped in between each use.

Since people can transfer germs (namely viruses) that are shed by horses to other horses, it is important to be careful about hand hygiene. Hand sanitizers containing at least 70% alcohol should be used after handling each yearling or at least after handling the group of yearlings.

What’s important to monitor during this time?

The earliest sign of an infection is often a fever so body temperatures should be taken daily. Monitor for signs of cough, discharge from the nose, and diarrhea. Discuss any unusual behaviour and concerns with your veterinarian.

What about vaccination and deworming?

Most of the conversations at sales involve pedigrees and conformation and little time is spent enquiring about the vaccination and deworming status of the newly purchased yearling.

Ontario breeders do an excellent job bringing healthy horses to the sale. Most, if not all, are well vaccinated and breeders usually provide a health paper stating the time and type of vaccination. If this information is not provided then it should be requested. It is important to know if the yearling will require a booster vaccination and, if so, when? Is it vaccinated for rabies, Eastern Equine Encephalitis (EEE) and West Nile? If not, it will be important to have your veterinarian administer these vaccines sometime during the winter months so that protection primarily for the mosquito-borne viruses (EEE and WNV) is provided for the summer/fall of the following year. This year there have been ten confirmed cases of EEE in Ontario so far with several suspected deaths. EEE is usually fatal in the unvaccinated horse. Make sure that vaccinations for respiratory disease, especially influenza, have been administered to reduce the likelihood of pneumonia and/or fatal complications.

Two often neglected questions are “When was the yearling last dewormed?” and “Was a fecal floatation or fecal egg count performed?” Yearlings and younger horses are very susceptible to parasite infestation, namely roundworms and sometimes tapeworms and cyathastomes. Roundworms are intestinal parasites that travel through the liver and lungs before inhabiting the small intestine. Fortunately, immunity to roundworms develops over the first two years of life. However, if the worm burden is high or the immunity is poor then problems can occur.

Deworming a yearling that has a large parasite burden may lead to an impaction from dead and dying worms and signs of colic or worse. There is evidence that roundworms on some farms in Ontario are resistant to ivermectin (a common deworming medication). Tapeworms can also cause signs of colic involving the small intestine and cecum and cyathostome infection may cause weight loss and diarrhea. Your veterinarian can perform a fecal test sometime after the yearling arrives home.

If you have any questions or concerns about biosecurity or the health of your new yearling, please consult your veterinarian.

Are you going to ship the yearlings in the same trailer you use to ship the racehorses?

Assuming the answer is yes (as in most cases), make absolutely sure that the trailer is cleaned and disinfected after the yearlings have arrived home. If you are racing Sunday night, at a minimum, clean the area where the noses have contact with the wall (e.g. left side in a slant load trailer and front in a front load) with soap and hot water. It is important to remove dirt and manure from the surfaces before cleaning and applying a disinfectant. Avoid using bleach or ammonia-based cleaners prior to transporting the racehorses as these products can release fumes which irritate the respiratory lining.

As you wander around the sale also keep in mind you don’t want to take any viruses home with you, so using a hand sanitizer in between touching horses is a great idea.